Information Processing in the Monkey Brain: We have been developing a transcortical (surface-to-depth) event-related potential (ERP) method to follow the path of cortical information processing across the monkey brain. The transcortical ERPs will be compared to neural activity in the monkey as well as to ERPs measured from the scalp in both monkeys and humans. Such comparisons will establish the neurophysiological and anatomical basis for the human ERPs that have been shown to be linked to interesting cognitive events. We map ERP across the brain during information processing of a go/no-go visual discrimination task in the monkey. The ERPs are recorded via transcortical (surface-to-depth) electrodes implanted in sets of up to 37 pairs in each monkey. Space-time images of that activity are then constructed. We have previously reported on the reliability, replicability, sensitivity to task manipulation of the data generated (see 1984 annual report).